Process for localized repair of graphene-coated lamination stacks and printed circuit boards

Abstract

Processes for localized lasering of a lamination stack and graphene-coated printed circuit board (PCB) are disclosed. An example PCB may include a lamination stack, post-lamination, that may further include a core, an adhesive layer, and at least one graphene-metal structure. A top layer of graphene of the graphene-metal structure may have never been grown before the lamination process or may have been removed post-lamination such that a portion of the top layer of graphene is missing. The localized lasering process described herein may grow (for the first time) or re-grow the graphene layer of the exposed portion of the metal layer without adverse effects to the rest of the lamination stack or PCB and while promoting a uniform layer of graphene on the top surface. A process of growing graphene through application of molecular layer and a self-assembled monolayer (SAM), are also described herein.

The invention claimed is: 
     
       1. A method of repairing one or more layers of a lamination stack or Printed Circuit Board (PCB) comprising:
 providing a layered structure, wherein an outer layer comprises a graphene-metal structure, and wherein the graphene-metal structure comprises a metal layer and an outer graphene layer disposed on the metal layer; 
 identifying a defect location in the outer graphene layer, wherein the defect location comprises an absence of graphene due to failed graphene growth or removal of the graphene post-growth on the metal layer, wherein the absence of graphene at the defect location exposes a portion of the metal layer; 
 preparing a surface of the outer graphene layer for repair, wherein the surface of the outer graphene layer comprises at least the defect location; and 
 applying localized heat to the defect location, 
 wherein application of the localized heat encourages growth of graphene in the defect location. 
 
     
     
       2. The method of  claim 1 , wherein preparing the surface of the outer graphene layer comprises cleaning a surface of the metal layer in the defect location prior to the application of localized heat. 
     
     
       3. The method of  claim 1 , wherein preparing the surface of the outer graphene layer comprises applying a molecular layer to the metal layer in the defect location. 
     
     
       4. The method of  claim 3 , further comprising baking the layers. 
     
     
       5. The method of  claim 4 , further comprising washing the lamination stack to clean an excess of the molecular layer. 
     
     
       6. The method of  claim 1 , wherein preparing the surface of the outer graphene layer comprises applying a self-assembled monolayer to the metal layer in at least the defect location. 
     
     
       7. The method of  claim 6 , further comprising washing the layers to clean the self-assembled monolayer. 
     
     
       8. The method of  claim 7 , further comprising baking the layers. 
     
     
       9. The method of  claim 1 , wherein the layered structure forms at least a portion of a Printed Circuit Board (PCB) and wherein the metal layer comprises a trace of the PCB. 
     
     
       10. The method of  claim 1 , wherein the layered structure forms at least a portion of a lamination stack. 
     
     
       11. The method of  claim 1 , wherein applying the localized heat comprises applying the localized heat via a laser. 
     
     
       12. The method of  claim 11 , further comprising determining a local temperature for configuring the laser, wherein the local temperature is determined by a laser power density and a laser scan rate. 
     
     
       13. The method of  claim 1 , wherein applying the localized heat comprises pulsing the localized heat. 
     
     
       14. The method of  claim 1 , wherein applying the localized heat comprises continuously applying the localized heat. 
     
     
       15. The method of  claim 1 , further comprising cooling the lamination stack at the defect location by pulsing the localized heat. 
     
     
       16. The method of  claim 1 , wherein the absence of graphene at the defect location is caused by a scratch or mechanical damage. 
     
     
       17. The method of  claim 1 , wherein the localized heat is incident on an outer two-dimensional material precursor of the defect location.